Train control system



P 3 w.-'-A. HARDCASTLE ET AL 2,053,370

TRAIN CONTROL SYSTEM Filed Aug. 11, 1928 9 Sheets-Sheet 1 WW/a/r/ E 291 5606776,

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Sept. V w. A. HARDCASTLE ET AL 2,053,870

TRAIN CONTROL SYSTEM I Filed Aug. 11, 1928 9 Sheets-Sheet 2 8, 1935- w. A. HARDCASTLE ET AL 2,053,870

TRAIN CONTROL SYSTEM 9 Sheds- Sheet 5 Filed Aug. 11, 1928 W. A. HARDCASTLE ET TRAIN CONTROL SYSTEM Sept. 8, 1936.

Filed Aug. 11, 1928 :////////IIII 9 Sheets-Sheet 4 p 1936- Q w. A. HARDCASTLE ET AL 2,053,870

TRAIN CONTROL SYSTEM Filed Aug. 11, 1928 v 9 Sheets-Sheet 5 Sept; 8, 1936. w. A. HARDCASTLE ET AL 2,053,870 r TRAIN CONTROL SYSTEM Filed Aug. 11, 1928 9 Sheets-Sheet 6= Sept. 8, 1936- w. A. HARDCASTLE ET AL 7 TRAIN CONTROL SYSTEM Filed Aug. 11, 1 928 9 Sheets-Shet 7 (992 C. Ali/7% I he/h aflney-st Sept. 8, 1936- w. A. HARDCASTLE ET AL 2,053,870

TRAIN CONTROL SYSTEM Filed Aug. 11, -1928 9 Sheets-Sheet 8 Z z o/ g w fl %%g g2 fl w e 2 Patented Sept. 8, l936 UNITED STATES PATENT OFFICE t. Louis Application August 11,

13 Claims.

This invention relates to improvements in train control systems, and consists in the novel construction and arrangement of parts, devices and connections hereinafter more fully disclosed.

An object of the invention is to provide an airoperated system under the influence of a device operable incident to a safe or unsafe condition of the track to apply and release the locomotive and train brakes in which, during an unsafe condition of the track, the manual control of the braking system by the operator is so modified that the normal operation of the locomotive or train is prevented until the track condition has been cleared and the control system manually reset by the operator.

Additional advantages of the construction will be fully apparent from the following description, taken in connection with the accompanying drawings in which Fig. 1 is a diagrammatic view of the' complete system.

Fig. 2 is a diagrammatic view of a valve constituting one of the controls for the system, said valve being shown in normal position and idemtified as the lap valve.

Fig. 3 is a view of the same valve in application position.

Fig. 4 is a diagrammatic view of another of the valves of the control system shown in normal position and identified as the main control I valve.

Fig. 5 is a view of the same valve in tion position.

Fig. 6 is a diagrammatic view of another of the valves of the control system in normal position and identified as the restoring valve.

Fig. 7 is a view of the same valve inapplication position.

applica- Fig. 8 is a diagrammatic view of another of Fig. 11 is a vertical section through an airoperated indicator associated with the control system and shown in normal position.

Fig. 12 is a diagrammatic view of an independent brake valve shown in normal or running position. 3

Fig. 13 is a vertical section through an equal- 1928, Serial No. 299,028

izing reservoir governor shown in normal or open position:

Fig. 14 is a vertical section through a main electrical control valve of the control system shown' in normal position.

Fig. 15 is a vertical section through a locomotive brake governor shown in normal or closed position.

Fig. 16 is a vertical section through a restricted exhaust safety valve shown in normal or closed position.

Fig. 17 is a vertical section through a locomotive brake governor control valve in normal or open position.

Fig. 18 is a vertical section through the equalizing reservoir governor in application or closed position.

Fig. 19 is a vertical section through the main electrical control valve of the control system in application position.

Fig. 20 is a vertical section through the locomotive brake governor in application or open position.

Fig. 21 is a vertical section through the restricted exhaust safety valve in application or open position.

Fig. 22 is a vertical section through the locomotive brake governor control valve in application or closed position.

Fig. 23 is a diagrammatic view of the distributing valve in normal or running position.

It will be understood broadly that the braking system is operated by the application and release of air pressure. This is accomplished through a system of pressure control actuated through a main electrical control valve that, in turn, is under the influence of the track condition. For convenience in description and clarity of disclosure it will be convenient to separatein a broad aspect the pressure control system and its controlling elements from the braking system per se; and these elements, for the sake of brevity, will be referred to as the control system.

In the embodiment of the invention illustrated in the drawings there is a main electrical control 45 valve i (shown in normal position in Fig. 14, and in application position in Fig. 19), which valve comprises an electrical field 2, said field being connected with a circuit comprising a lead 3 and 4 forming a circuit with electrical energizing 5 means that function during clear track conditions to energize the field 2. This circuit actuates an armature which'is held in a raised or normal position, as illustrated in Fig. 14, against the tendency of a spring 6. The armature has connected as therewith a pair of valve stems I and 8 which carry, respectively, a double valve body 9 and I6, and II and I2. The valve l0 seats at l3, and the valve seats at l4.

In the body of the valve there is a passage |5 that connects into a chamber l6. A seat at the lower end of the chamber l6 constitutes a port from the chamber |6 to a passage l6, which passage I8 is connected with a chamber l9. The seat |3 constitutes a port from the chamber l9 to a passage 20. There is a passage 2| that connects into a chamber 22, and the seat l4 constitutes a port from the chamber 22 to the chamber l6. A seat 23 constitutes a port from the chamber 22 to the passage 20.

The control system also includes a valve 24, identified as a main control valve, which valve is shown in detail in normal position in Fig. 4 and in application position in Fig. 5.

This valve comprises a cylinder in which there is a movable element 25 which functions as a piston. The member 25 is designed as a double action piston having pressure chambers at each end thereof. there is an expansion spring 26, the function of which is to control the valve in the normal position to which it is actuated by pressure admitted to the chamber in which the spring is seated. It is to be understood that the adjustment of the tension of the spring 26 is such that it does not operate as a power element, but operates merely as a detent for holding the piston in normal position. A conduit 21 connects into the application chamber of the valve. A conduit 28 connects into the opposite chamber or normal chamber of the valve. The functioning of the valve 24 will be more fully described hereinafter.

Another element of the control system is an exhaust control valve 29, shown in detail in normal position in Fig. 8 and in application position in Fig. 9. The valve 29 is similar in construction to the valve 24 and functions and operates in substantially the same manner. It includes a double piston 36 operating in a cylinder in which there is a spring 3|. A conduit 32 connects into the application chamber thereof; and a conduit 33 connects into the opposite chamber or normal chamber. The functioning of the valve 29 likewise will be more fully described hereinafter.

Another element of the control system is a valve 34, shown indetail in normal position in Fig. 2 and in application position in Fig. 3. The valve 34 likewise has a double action piston 35 that is mounted in a cylinder or housing in which there is a spring 36 at one end of the piston. The spring 36 operates in a manner similar. to the springs 26 and 3| in the valves 24 and 29, respectively. .There is a conduit 31 that connects into the application chamber thereof. A conduit 38 connects into the opposite end of the valve cylinder or normal chamber. In making general reference to the valve 34 it will be referred to as the lap valve. Its function will be more fully described hereinafter. Y

Another element of the control system is the valve 39 which will be referred to as the restoring valve, and which is shown in normal position in Fig. 6 and in application position in Fig. 7. The valve 39 is of the same general construction as the valves 24, 29 and 34, with the exception that it is provided with a plunger 40 at the end of a double acting piston 4| and with a spring 42 at the opposite end of the piston. The spring 42 operates as a power element to force and hold the valve in normal position. The valve is manually ment by the spring, as illustrated in Fig. 11.

In one of the pressure chambers operated in the direction in opposition to the spring by pressure applied to the plunger 40.

There is associated with the control system an air-operated indicator 43, shown in detail in Fig. 11. This indicator comprises a cylinder 44 in which there is a spring-operated piston 45. The piston is normally held in the downward adjust- A piston rod 46 is connected with the piston 45 which, for the purpose of assembly, may be made in two sections. The upper end of the piston rod 46 carries a bracket 41 to which is attached a rack bar 48. The bracket 41 has a pair of pins 49 and 56 on its upper face and the rack bar has a socket at its lower end so that it may be positioned and set on either of the pins 49 or 50. This permits the actuation of the semaphore arm in either direction, as desired.

The rack bar 48 meshes with a pinion 5| carried by a support 52, said support having connected therewith a semaphore arm 53. When the piston 45 is in its downward adjustment in the cylinder the semaphore arm is in the position shown in Fig. 11 and serves to indicate a condition of the control system. It should be understood that the air-operated indicator does not affect the other elements of the control system, its purpose being merely to provide a visible means for indicating to the operator 2. position of the main electrical control valve I and the position of the main, control valve 24 under certain operative conditions to be described more fully hereinafter.

There is also associated with the control system a whistle 54 (Fig. 1) which is of known construction and is incorporated in the system as a means for indicating the position of the control system audibly when air pressure is admitted thereto. The whistle 54 does not affect the other elements of the control system. Its function in the operation of the system will be made apparent hereinafter.

When the control system is in normal position there are certain parts of the system supplied with pressure, others are open to atmosphere, and others in which there is no pressure and no exhaust. These conditions may be considered in the nature of an advance setting of the system to insure that it will assume the application position when operated to that end, and it will first be assumed in this description that this advance setting or normal position exists and the condition of the system thus considered will now be described.

Air pressure for the operation of the control system originates at the main reservoir 55. The pressure in the main reservoir 55 is induced and maintained by a pump in the usual manner. Under ordinary conditions the main reservoir carries approximately ninety pounds gage pressure which is a satisfactory pressure for usual operations. A conduit 56 is connected into the main reservoir and connects at 51 with a conduit 58 that branches at 59 into a conduit 66, said conduit 66 connecting into the main electrical control valve. Therefore, it is apparent that the conduit 60 is at all times supplied with the main reservoir pressure and irrespective of the position of the control system. There is another conduit 6| that branches at 59 and leads to the main control'valve 24 thereby supplying said valve with main reservoir pressure at all times and irrespective of the position of the control system.

The field 2 of the valve is normally energized by a circuit closed over the leads 3 and 4 through the engine control relay or other means during and throughout a clear condition of the track. When the field 2 is energized the valve I is in its normal position in which the armature 5 is held in raised position against the tendency of the spring 6. Therefore, main reservoir pressure is delivered by the conduit 60 to the passage I5 through the chamber I6 and the port I I to the passage I8, thence into a conduit 62 through a passage 63 of the valve 39 and to a conduit 64 where it is shut oil? by the movable member or piston 30 of the valve 29.

In this advance setting or normal condition of the system the application chamber of the valve 24 is exhausted to atmosphere through the conduit 21, the passage 2|, the chamber 22 and the port 23 to the passage 20 of the valve I; and thence to a multiple exhaust conduit 65, which conduit is open to atmosphere.

A conduit 66 connects the main control valve 24 with the restoring valve 39 and is closed by the piston II in said valve 39. At its opposite end the conduit 66 is connected with a conduit 61 through a groove 68 of a passage 69. Since the conduit 61 connects with the conduit 21 and the conduit 21 is open to atmosphere, as above described, it is evident that there will be no pressure in the conduits 66 or 61. The normal chamber of the valve 24in this setting of the system is exhausted to atmosphere through the conduit 28 connecting thereinto, which conduit connects with a groove 10 of a passage II in the piston 30 of the valve 29; thence to a conduit I2 to the multiple exhaust conduit 65.

The application chamber of the valve 29 is closed. The conduit 32 leads from said application chamber to a conduit I3 which is closed at one of its outlet ends by the piston 4| of the valve 39 and at its other outlet end by the piston 25 of the valve 24. The normal chamber of the valve 29 is connected to atmosphere through the conduit 33, a passage 14 in the piston 4| of the valve 39, a conduit I5 and a conduit 16, said conduit I6 connecting into the multiple exhaust conduit 65.

The application chamber of the valve 34 is connected to atmosphere through the conduit 31 connecting into said chamber, a passage II of the piston 30 of the valve 29, a conduit 10, a restricted passage I9 in the piston 4| the valve 39 and a conduit 80 which connects into a multiple exhaust conduit 8|.

A conduit 82 which .branches at 83 from the conduit 31 is closed by the piston 25 of the valve 24. Since the conduit 3'Iis exhausted to atmosphere, as above described, it follows that there will be no pressure in the conduit 82 in this setting v of the system.

The normal chamber of the valve 34 in this setting of the system exhausts to atmosphere through the conduit 38 connected thereto which leads through a restricted branch opening of the passage 14 of the piston 4| of the valve 39; thence to the conduit I which connects with the conduit I6, one end of said conduit I6 connecting into the multiple exhaust conduit 65.

The conduit 6| which is supplied with main reservoir pressure during all operations of the system connects with a passage 84 in the piston 25 of the valve 24. The passage 84 has a groove 85 which connects with a conduit 86 leading to the valve 39. Therefore, main reservoir pressure delivered by the conduit 6| is conducted to the valve 39 by the conduit 86 which is closed by the piston -4I of the valve 39.

A conduit 81 which connects the exhaust control valve 29 with the restoring valve 39 in the condition of the system now under consideration is closed at both ends at the valves 29 and 39 by the piston elements thereof.

A conduit 89, which connects the main control valve 24 with the air-operated indicator 43, is exhausted to atmosphere through a passage 89 in the piston 25 of the valve 24,,and a conduit 90. Therefore, there is no pressure in the cylinder 44 to actuate the spring-actuated piston 45 and the semaphore remains in a position to indicate that'the main control valve 24 is in normal position.

The audible means for indicating the condition of the control system to the operator provided by the whistle 54 remains inoperative so long as the control system is in normal position. A conduit 9| is closed by the piston 25 of the valve 24, said conduit 9| being in communication with a passage 92 in the piston 30 of the valve 29, a conduit 93, a passage 94 in the piston 35 of the valve 34, a conduit 95 and a conduit 96. which is connected with the whistle 54. The opposite end of. the conduit 96 is closed by the piston 35 of the valve 34. Since the whistle 54 itself constitutes an exhaust -to atmosphere at all times, there will be no pressure in the conduits and passages last above mentioned.

The above outline of the condition of the control system when in normal position has been thus generally described to indicate the conditions of pressure and exhaust obtaining in this normal setting of the system as a basis of further description in proper sequence of its operation, when actuated to application position and its return to normal position.

It will be convenient at this point to briefly outline the construction of the elements of the braking system.

The braking system includes as an element an automatic brake valve 91, shown in detail in Fig. 10. I he body of the valve is stationary and acts as a seat for a rotary valve element 98 in the upper part thereof, said valve 98 being manually operated to its different adjustments. In the central portion of the body there is an equalizing piston 99 which comprises a piston body I00 and a piston ring IIlI operating in a cylinder I02 that connects the walls of chambers I03 and I04 located above and below the piston 99, respectively. There is a recessed portion I05 on the under face of the piston I00 and mounted in said recess is a recessed cylindrical head I06 on an equalizing piston stem I01. An expansion spring I09 is seated in the recess in the piston I00 and in the head I06. The equalizing piston stem I0! is mounted for sliding engagement in the top.

wall of a valve housing I09. In the bottom wall of said housing I09 is a valve seat against which the lower portion of the equalizing piston stem I01 seats. There is a series of outlet ports 0 which communicate with the chamber I 04. A cylindrical extension III is connected into the lower end of the valve housing I09, said extension having its upper end directly connected into a passage in the valve housing and its lower end formed with an opening therethrough which acts as a guide for the stem of a preliminary exhaust valve 2, which will be described in further detail hereafter. It will be understood that the stem of the preliminary exhaust valve is formed separate from the piston stem I 01, but that the upper end of the stem of the preliminary exhaust valve abuts against the lower end of the piston stem I01. The cylindrical extension III has a port I I3 through the wall thereof which exhausts to atmosphere.

A passage II4 which is connected with a conduit II5 leads to a chamber H6 above the valve member 98. There is a passage I I1 in the rotary valve 93 that connects the chamber II6 with a passage H8 through the body of the valve, which passage I I8 connects at its outlet end with a conduit II9. A passage I20 in the body of the valve has connected thereinto a conduit I2I, said passage I20 connecting into a passage I22 in the rotary valve 98 which, in turn, connects with another passage I23 in ,the valve body, said passage I23 communicating with another passage I24 in the valve body, said passage I24 leading to a passage I25 in the rotary valve 98 and thence to a passage I26 in the valve body that connects into the chamber I03.

The passage I23 also connects with a passage I21 in the body of the valve, said passage I21 having connected thereinto a conduit I28. The chamber I03 connects with an equalizing reservoir I29 by means of a passage I30-leading from the valve body to a conduit I3I opening into the equalizing reservoir I29. The equalizing reservoir I29 and the chamber I03 are therefore in permanent communication to provide a combined air space, the purpose of which will appear hereinafter.

There is a passage I32 in the body ofthe valve which connects with a conduit I33 which passage I32, in turn, connects with a passage I34 communicating with the chamber I04. The ports I I from the chamber I04 are normally closed'by the equalizing piston stern I01. There is a passage I35 in the body of the valve which connects with a conduit I36.

The upper end of the passage I35 is closed at its upper or outlet end by the rotary valve member 98. A passage I31 in the valve body connecting at one end with a conduit I38 is connected through a passage I39 in the rotary valve member 98 with a passage I40 in the body of the valve. Said passage I40, in turn, is connected with an exhaust passage MI in the valve body, said passage I4I being open to atmosphere at its outer end. There is also a passage I42 in the valve body that connects with the passage I40 which is closed at its outlet end by the rotary valve 98.

A passage I43 in the valve body connects into the passage I31 which is closed at its outlet end by a plug I44 and at its opposite end by the rotary valve element 98. A passage I45 in the valve body leads to the outer wall of the valve body and is closed at its outlet end by a plug I46 and at its opposite end by the rotary valve 98. A passage I41 in the valve body connects at one end into the chamber I03 and is closed at its upper restricted outlet end by the rotary valve 98.

The braking system also includesthe preliminary exhaust valve I I2 which is connected to and functions with the automatic brake valve 91. By reference to Fig. 10 it will be noted that the prelimina'ry exhaust valve H2 is connected to the body of the automatic brake valve 91 by a cylindrical extension I48, said extension forming a chamber I49 which is connected to atmosphere by a port I50 through the 'wall thereof. To the lower end of the cylindrical extension I48 is connected a valve housing II which forms a chamber I52 into the lower wall of which a conduit I53 is connected.

In the chamber I52 there is a flap valve I54. The flap valve I54 comprises a central valve ele- -I19 through the valve body ment I55 which has pivot connection at one end with a lug I56 formed on the inner wall of the chamber I52 and on each side of the central valve element I55 is a valve gasket I51 and I58, respectively. The lower wall of the chamber I52 has a valve seat I59 against which the valve gasket I51 seats when the valve is in depressed or closed position. There is a valve seat I60 in the upper wall of the chamber I52 against which the valve gasket I58 seats when the valve is in raised or open position. A stem I6I extends axially through the valve body which includes the elements I55, I51 and I58 and said stem carries a coiled expansion spring I62. It will be noted that the spring I62 extends beyond the end of the stem I6I and bears against an enlarged portion I63 of a stem I64 which is located axially in the chamber I49. The stem I64 extends through an opening in the member III, said member III being cylindrical in form, and has an opening in one end to accommodate said stem, whereby the upper end thereof is held in alinement. The spring I62 tends to force the stem I64 upwardly so that its end lies adjacent to the lower end of the stem I01. A bracket I65 is carried by the flap valve, said bracket extending upwardly from its upper face and said bracket carrying at its upper end a bifurcated arm I66 that extends inwardly from said upper end of the bracket. The extremities of said arm extend over the upper shoulder formed by the member I63. The space between the arms of the bifurcated member is of suflicient depth that, when the valve is in depressed position, said arms will be out of contact with the stem I64 and out of contact with the member I63.

The chamber I52 is vented to atmosphere through a preliminary exhaust port I61 cut through the wall of the valve housing I5I. The port I61 is relatively small in diameter and therefore a relatively slow exhaust of pressure in the chamber- I52 results.

The independent brake valve I68 shown in Fig. 12 of the drawings is another element of the braking system, the essential portions of which may be generally described as follows:

The body of the valve is stationary and constitutes a seat for a rotary valve element I69 located in the upper part thereof. The valve element I69 is manually operated to its different adjustments.

There is apassage I into which connects a conduit I1I. The passage I10 is in registration with a passage I12 in the rotary valve element I69 in all positions of the valve. The passage I12 connects into a chamber I13 located in the upper part of the valve housing and above the rotary element I69. There is a passage I14 in the body of the valve which is closed at its upper end by the rotary valve element I69 and the opposite end of said passage I14 opens to atmosphere. A passage I into which connects a conduit I16 is closed at its upper end by the rotary valve element I69. A passage I11 in the valve body has connected to its lower end a conduit I18 and said passage is closed at its upper end by the rotary valve element I69. A passage conduit I80 at its lower end, said passage I19 communicating at its upper end with a passage I8I in the under face of the rotary valve element I69 by means of which it communicates with another passage I82 in the valve body, said passage I82 having a conduit I83 connected into its lower end.

is connected with a.

Another element of the braking system is an equalizing reservoir governor I84 shown in detail in Figs. 13 and 18, in the former of which the governor is shown in normal or open position and in the latter of which it is shown. in application or closed position.

The equalizing reservoir governor comprises a body portion I85 which, for the purpose of convenience of assembly, is made in two sections. A top member is attached to the upper end thereof. The governor top includes a piston I88 which is fitted for sliding engagement in a diaphragm ring I81 mounted in the top of a chamber I88 and the upper member of the body of the equalizing reservoir governor body I85. The piston I88 is circular in form and has extending axially therethrough a pin. valve I89, the tapered end of which is adapted to seat in an opening I90 at the bottom of the chamber I88 when the piston is in depressed position.

A strong expansion spring I9I is mounted above the head piece of the piston I88, the upper end of said spring contacting with a screw plug I92 threaded into the upper end of a housing I93. Said screw plug is adjustable in the housing and therefore serves to adJust the tension of the spring I 9| A cap nut I94 fits over the upper end of the housing I93, said cap nut being removable to permit access to the plug I92 for adjustment. There is a vent port I95 through the wall of the housing I93 which permits any pressure caused by leakage past the piston to escape from the housing I93.

The tension of the spring I9I is adjusted to withstand a predetermined maximum range of pressure in the chamber I 88. That is to say, as

' long as the pressure in the chamber I88 remains within the predetermined limits, the piston will remain in raised position holding the pin valve I89 from its seat, as shown in Fig. 13. When the pressure in the chamber I88 drops below the tension for which the spring I9I is set, said spring will operate to force the pin valve I89 to its seat I90, as shown in Fig. 18.

A passage I98 connects into the chamber I 88, said passage I98 extending through the body of the device. The lower end of the passage has connected thereinto a conduit I91. The chamber I88 is in communication through the valve port I90 with a passage I98 in the body of the device, said passage I98 communicating with a chamber I99 formed in the body or the member. There is a branch passage 200 that communicates with the passage I98 at its upper end and extends downwardly through the body portion of the device and has a conduit 20I connected to its outlet end.

A piston 202 is mounted in the chamber I99, the piston being actuated by a spring 203 disposed against the under face of the piston. The piston 202 is connected with a valve stem 204 that carries a valve plug 205 at its lower end. The piston operates in a cylinder casing 208 mounted at the top of a chamber 201 in which the valve plug 205 operates.

The chamber 201 has connected thereinto a passage 208 which leads to the exterior of the body of the device and connects with a conduit 209. There is a valve port 2I0 in the bottom of the chamber 201, said port constituting a seat for the valve plug 205. .The chamber 201 is in communication with a passage 2 leading to the exterior of the body of the equalizing reservoir governor through the port 2I0. -A conduit 2I2 connects with the lower end of the. passage 2. There 'is a passage 2I3 that connects through the wall 01' the cylinder 208, said passage constituting a bleed port to relieve the pressure in the cylinder 208 induced by air that may leak past the piston 202 from the chamber I99 or that may leak past the valve stem 204 and the chamber 201, thus preventing pressure from being trapped beneath the piston 202 and thereby preventing any pressure that may be above the piston 202 forcing it down against the tension of the spring 203.

Another element 01' the brake system includes a locomotive brake governor indicated by 2I4, 15 and 20, in

the former of which the device is shown in nor- .mal or closed position and in the latter in application or open position. This element is of the same general construction as the equalizing reservoir governor and it will, therefore, be unnecessary to redescribe its construction in detail. However, to avoid confusion in the description of its operation, the operative parts thereof will be given separate reference numerals as follows:-

The body is indicated by 2I5 and the piston by 2I8, the diaphragm ring by 2I1, the chamber below the diaphragm by 2I8, the pin valve by 2I9, the seat for the ating spring by 22I, the screw plug by 222, the housing by 223, the cap nut by 224, the vent port by 225. A passage 228 connects the chamber 2I8 with a conduit 221. A passage 228 connects the chamber 2I8 with a chamber 229 through the port 220. A passage 230 branching from the passage 228 connects into a conduit 23I. A piston 232 is actuated by a spring 233. .The valve stem is indicated by 234, the valve plug by 235, the cylinder casing by 238, a chamber by 231. A passage connecting the chamber 231 with a conduit 238 is indicated by 239. A port 240 communicates a passage 2 with the chamber 231, said passage having connected thereto the conduit 209.- -A passage 242 constitutes a bleed port a housing 244 in which is located a valve 245.

The valve 245 controls a passage 248 through the valve that connects with a conduit 241. The valve 245 is actuated to closed position by an expansion spring 248 that surrounds a stem 249, the lower end or which spring bears against the upper face 01' the valve 245. The valve 245 operates in a chamber 250, from which there is an exhaust port 251. Leading from the top of the chamber 250 is a passageway 252 that communicates with a chamber 253 formed in the upper part of the housing 244 of the valve and exhaust ports 254 lead from the chamber 253. The end of the passage 252 that enters the chamber 253 and the exhaust port 25I are controlled by the movement of the valve 245 operating as a slide valve to control the outlet openings of the passages 25I and 252. The tension of the spring 248 is adjustable and acts as a guide for the stem 249 is provided for the adjustment of said spring. The screw plug 255 is threaded into the housing 244 for adjustment. A cap nut 258 is screwed to the screw plug 255.

The braking system also includes a locomotive brake governor control valve 251, shown in detail in Figs. 17 and 22, in the former of which this a screw plug 255 which also pin valve by 220, the opervalve is shown in normal or open position and in the latter in application or closed position.

The valve 251 comprises a housing 258 in which there is mounted a valve 259, said valve controlling a passage 260 that has connected thereto the conduit 23L The valve 259 is normally actuated to downward or open position by an expansion spring 26I that surrounds a stem 262, the lower end of which bears against the upper face of the valve 259. The valve 259 has a restricted passageway 263 therethrough that communicates with a chamber 264. At the top of the chamber 264 there is a passageway 265 that communicates with a chamber 266 formed in the upper part of the housing 258 and there is an exhaust port 261 leading from said chamber 266. When the valve 259 is in downward adjustment there is a restricted exhaust through the passage 263 to atmosphere. Where the upper end of the passage 265 enters the chamber 266 it is controlled by the movement of the valve 259 that operates as a slide valve to control said outlet passage 265. The tension of the spring 26I is adjusted by a screw plug 268 which also serves as a guide for the stem 262. The screw plug threads into the upper end of the'housing 258 and a screw cap 269 is threaded over the extremity of the plug 268 and extends beyond the housing.

The braking system also includes a distributing valve 210, shown in Fig. 23. The distributing valve is adapted to apply and release the locomotive brakes by control of pressure admitted thereto or exhausted therefrom which is accomplished under ordinary conditions by manual manipulation of the automatic brake valve 91 and the independent brake valve I68.

The distributing valve 210 is divided into two portions, one designated the application portion and the other the equalizing portion. It is attached to a double chamber reservoir which, for convenience of illustration and description, is shown in the drawings as part of the valve itself. The application portion of the distributing valve includes an application cylinder 21I in which there is mounted an application piston 212 provided with a graduating spring 213. A chamber 214 positioned at the right of the piston 212 (Fig. 23) surrounds the piston and spring and also an exhaust valve 215 which is actuated by the piston 212. A pasage 216 leads through the exhaust valve. The application piston 212 has a piston stem 211 that connects with an application valve 218, the application valve being provided with a passage 219. The application valve 218 is surrounded by a chamber 280 which is connected by a passage 28I to a conduit 282. The chamber 214 is permanently connected by a passage 283 in the body of the valve with a conduit 284 that leads to the brake cylinders of the locomotive and tender. Said passage 283 connects with the chamber 214 at two places and also branches to the exterior of the valve, said branch being normally closed' by a plug which may be removed for the purpose of drainage when necessary.

A passage 285 in the body of the valve also connects into the chamber 214 at two places, said passage 285 constituting an exhaust passage to atmosphere. The passage 285 is controlled by the movement of the exhaust valve 215 which, in turn, is actuated .by the application piston 212. The equalizing portion of the distributing valve 210 includes an equalizing piston chamber 286 in which is mounted an equalizing piston 281 application chamber which actuates a graduating valve 288 and an equalizing slide valve 289.

The chamber 286 into which a conduit 290 connects has a feed groove 29I in its upper wall that connects the chamber 286 with an equalizing slide valve chamber 292, said chamber 292 surrounding the piston 281 and the valves 288 and 289. The chamber 292 is permanently connected by a passage 293 to a pressure chamber 294. In the wall of the chamber 286 is a graduating stem 295 and a graduating spring 296. The graduating valve 288 is provided with a passage 291, and the equalizing slide valve 289 is provided with passages 298, 299, 300, 301 and 302. A passage 303 permanently connects the application cylinder 21l with a conduit 304, said passage 303 branching into three outlet passages in the body of the valve beneath the equalizing slide valve 289. A passage 305 extends through the valve and has connected to its outer end the conduit I80. A passage 306 is permanently connected into an 301 and a passage 308 is permanently connected with a safety valve 309.

The remaining elements of the braking system, including a reducing valve 3I0, a train control feed valve 3| I, a feed valve 3I2, a check valve 3I3,

a train control feed valve safety valve 3| 4, a double-heading cock 3I5 and a pump governor 3l6, are of usual and known construction and it will only be necessary to give a brief description of their functions in connection with the description of the operation of the braking system.

In describing the operation of the control elements of the braking system and their relation one to the other as a braking system it will be assumed that the position of the elements I, 24, 29, 34 and 39 of the control system are in normal position; and likewise that the automatic brake valve, the preliminary exhaust valve. the independent brake valve, the equalizing reservoir governor, the locomotive brake governor, the restricted exhaust safety valve, the locomotive brake governor control valve and the distributing valve are all in normal position.

It will be understood that in the operation of the braking system certain of the conduits and control elements are supplied with air pressure at all.times and irrespective of the position of the control elements of either the control system or the braking system.

The air pressure for the operation of the braking system originates in the main reservoir 55, said pressure being induced as hereinbefore described, and is maintained at about 90 pounds. Pressure from the main reservoir is delivered to the valve 34 through the conduit 56. The conduit 56 is, therefore, supplied with main reservoir pressure at all times, regardless of the position of the movable member 35 of the valve 34.

The conduit 56 branches at 3" and connects with a conduit 3I8 leading to the reducing valve 310. The reducing valve 3l0 is of known construction and its function is merely to reduce the main reservoir pressure.

In practice, if the main reservoir pressure is approximately 90 pounds, the pressure is. re-

duced by the valve 3l0 to approximatelypounds maximum pressure.

The outlet conduit I1I leads from the valve 3l0, which conduit connects into the passage I10 of the valve I68, said passage I10 registering in normal or running position as well as in other positions of the brake valve with the passage I12, thereby conducting the reducing valve pressure Into the chamber I13 above the rotary valve eleof the valve 34 and a conduit 332 to the low presment I69 at all times. The purpose of thus introducing pressure above the rotary valve element is to hold said element to its seat and to have available reducing valve pressure for locomotive brake applications under other adjustments of the valve I68.

A conduit 3I9 which leads from the reducing "valve 3! to the valve 24 is also supplied with reducing valve pressure to the maximum pressure of 45 pounds at all times. The conduit 3I9 is closed at its outlet end by the movable member 25 of the valve 24.

It will be noted that the conduit 56 branches at 320 into the conduit 282 which connects into the distributing valve210. Since the conduit 282 connects into the passage 28I of the distributing valve, said passage 28I, in turn, connecting with the chamber 280 surrounding the, application valve 218, it is evident that the chamber 290 will be constantly supplied with main reservoir pressure. The main reservoir pressure in the chamber 280 makes .constantly available pressure for the application of the locomotive brakes.

The conduit 56 also branches at 32I into a conduit 322 leading to the train control feed valve 3I I. The train control feed valve 3 functions to reduce the main reservoir pressure to approximately 49 pounds maximum. The reduced pressure is conducted constantly through a conduit 323 to the valve 34.- The conduit 323 is closed at its outlet end by the movable member 35 of the yalve 34.

The conduit 56 again branches at 324 into a conduit 325 leading to the feed valve 3I2. The feed valve 3 I 2 reduces the main reservoir pressure to approximately 70 pounds. The reduced pres- .sure of the feed valve 3I2 is connected to the iyalve 34 by a conduit 326. The "conduit 326 is, therefore, constantly supplied with feed valve pressure, thereby maintaining available a mode :termined pressure for the brake pipe or train line through the automatic brake valve, thereby compensating for any leakage in the system.

A conduit 321 which connects the main reservoir 55 with the high pressure head 328 of the pump governor 3I6 is also supplied with main reservoir pressure at all times. The high pressure head 328 is inoperative in the normal or running position of the brake system.

In the description heretofore given in relation to the supply of pressures it has been assumed that the pressures were supplied regardless of the position of the control elements. The following description assumes that the pressures are placed under the control of the control elements.

It ,Will be remembered that the conduit 56 is .;supplid with main reservoir pressure at all times. This pressure is conducted through a passage 329 of the valve 34 to a conduit 330 which connects into the check valve 3I3. The opposite end of the valve is connected by the conduit I I5 with the valve 91. The check valve 3I3 is of usual construction and acts as a back pressure valve reversely to the'flow of pressure through the conis duits 330 and H5. The conduit I I5 connects with the passage I I4 of the valve 91 which leads to the chamber I I6 above the rotary valve 98. The purpose of delivering main reservoir pressure to the top of the rotary valve is to hold the rotary valve '0 to its seat and to have main reservoir pressure available for recharging the braking system, as will be described hereinafter.

Main reservoir pressure from the chamber H6 is conducted through the passages H1 and I I8 5 of the valve 91, the conduit I I9, a passage 33I sure head 333 of the pump governor 3 I6.

The function of the low pressure head 333 of the pump governor 3I6 is to control the operation of the pump for maintaining pressure in the main reservoir 55 when the system is in normal or running position. When the pressure remains within the normal operating limits the pump is idle. When the pressure in the conduit 332 and, therefore, the pressure in the low pressure head 333 of the governor 3I6 drops below the predetermined minimum a steam valve 334 will operate to initiate operation of the pump by admitting steam thereto. When the pressure again rises sumciently to bring the pressure in the low pressure head 333 of the governor 3I6 within the normal operating limits the operation of the pump is stopped. In normal or running position of the trol system the high pressure head 328 of the governor 3I6 does not function because the setting of the valve in the high pressure head is such that it will not be operated to control the pump by the low pressure that is supplied through the conduit 321 directfrom the main reservoir 55.

It will be remembered that the conduit 326 is supplied with a predetermined feed valve pressure at all times. This pressure is conducted through a passage 335 of the valve 34, the conduit I2I, and the passages I20, I22, I23, I24, I25 and I26 to the chamber I03 on the upper side of the equalizing piston 99-. As a result of these connections a predetermined pressure is maintained in the chamber I03 and hence against the upper side of the equalizing piston 99 by the feed valve 3I2. The chamber I03 is connected by the passage I30 and the conduit I3I re the equalizing reservoir I 29 which obviously will have an internal pressure equal to that in the chamber I03. The conduit I91 connects the equalizing reservoir I29 with the equalizing reservoir governor I84, the conduit I91 connecting into the passage I96 of the governor I84 which leads to the chamber I88 beneath the piston I86.

In order to bring out the operative features of the device it will be assumed in the present description that the spring tension of the spring I9I is adjusted to withstand a pressure of fifty pounds beneath the piston I86 and since it will not overcome the pressure in the chamber I88 the piston will raise the pin valve I89 from its seat I90. Therefore, so long as the passage I96 maintains a predetermined pressure in the chamber I88 the port I90 will be open, thus connecting the chamber I88 with the chamber I99 through the passage I98 and also by the passage 200 and the conduit I with the valve 34. The outlet end of said conduit MI is closed by the movable member 35 of the valve 34.

From the connections described it is obvious that the chamber I03 above the equalizing piston 99, the equalizing reservoir I29 and the chambers I88 and. I99 will have an equal pressure which, under the initial pressure assumed, will be approximately 70 pounds supplied from the feed valve 3I2. In connection with the equalizing reservoir governor I84 it should be noted that the piston 202 with its attached valve plug 205 is forced downwardly against the tension of the its seat 2I0. The valve plug 205 therefore acts as a control for the passage 2 and the chamber 201.

The passage I 23 of the valve 91 is supplied with feed valve pressure as above described. It should be noted that the passages I23 and I21, the conduit I28, a passage 336 which intersects a passage 331 of the valve 34, the conduit I33 and the passages I32 and I34 of the valve 91 connecting into the chamber I04 will maintain a pressure of '70 pounds in the chamber I04 and against the under side of the equalizing piston 99. The pressure on both sides of the equalizing piston 99 will be equal and, therefore, the stem I01 will be held to its seat to close the exhaust ports H in the lower part of the chamber I04 holding the pressure in said chamber.

With reference to the passage 331 of the valve 34 that is supplied with feed valve pressure, as above described, it will be noted that said passage 331 connects at its lower or outlet end with a conduit 338 that forms a branch of a brake pipe 339. The conduit 338 has interposed therein the double heading cock 3l5 of known construction and the normal position of which is open. The conduit 338 connects into the extension 339 of the brake pipe of the train brake system. As a result of these connections it will be understood that a feed valve pressure is maintained in the train brake line, thereby holding the air brakes in release position on the train. The pressure in the train brake line will be equal to the pressure in the chambers I03 and I04 of the valve 91 and to the pressure in the equalizing reservoir I29.

Another extension 290 of the brake pipe line 339 leads from the conduit 338 to the distributing valve 210. The conduit 290 connects into the equalizing piston chamber 286 and, as the normal feed valve pressure is delivered thereto through the connections above described, the equalizing piston 281 is moved to a position in which the feed groove 29I connecting into the equalizing slide valve chamber 292 is open. The chamber 292 is in turn permanently connected to the pressure chamber 294 through the passage 293. As the ports of the equalizing slide valve 289 are closed by the graduating valve 288 when the distributing valve is in running position, it is obvious that the equalizing piston chamber 286, the equalizing slide valve chamber 292 and the pressure chamber 294 will have an air pressure charge equal to the pressure in the brake pipe 290.

While the pressures on both sides of the equalizing piston 281 remain equal; that is to say, the pressures in the equalizing piston chamber 286 and the equalizing slide valve chamber 292, the equalizing piston actuates the graduating valve 288 and the equalizing slide valve 289 to the left, as shown in Fig. 23. The result of this adjustment of the equalizing slide valve 289 is the connection of certain passages in the body of the valve beneath the equalizing slide valve 289. The result of the connection of these passages is the control of certain passages in the elements of the control system and certain passages, chambers and conduits of the braking system. For purposes of clearness of description these passages, chambers and conduits will be grouped and described separately, following which the control of the same by the equalizing slide valve 289 will be described.

The first group concerns the application cylinder connections. This group includes the application cylinder 2" of the distributing valve 210 (Fig. 23) which is permanently connected with the equalizing slide valve body by the passage 303 which branches into three outlet openings in said valve body beneath the equalizing 'tributing valve 210 (Fig. 23)

slide valve 289. The passage 303 has connected thereinto the conduit 304 which branches at 340 into the conduit I16 which connects with the passage I15 of the independent brake valve I68 (Fig. 12). The conduit 304- branches at 34I into the conduit I36 which connects with the passage I35 of the automatic brake valve 91 (Fig. The conduit 304 also branches at 34I into the conduit 221 which connects with the passage 226 terminating in the chamber 2I8 of the locomotive brake governor 2I4 (Figs. 15 and The conduit 304 also branches at 34I into the conduit 238 which connects with the passage 239 terminating in the chamber 231 of the locomotive brake governor 2I4 (Figs. 15 and 20) From the above description of the application cylinder connections it will be obvious that the pressure conditions in these connections will be the same as those in the application cylinder 21 I. This group of connections is not changed by a change of position of any of the elements of the control or braking system as they are permanently connected in all positions assumed in the different operations or adjustments affecting the system.

There is another group of connections relating to the release of the distributing valve and which concern the distributing valve release connections. This group includes the passage 305 in the body of the equalizing slide valve of the dis- Said passage 305 connects with the conduit I80 which connects with the passage I19 of the independent brake valve I68 (Fig. 12), said passage I19 being connected with the passage I82 by the passage I8I in the valve I68. The passage I82 connects with the conduit I83 which is connected with a conduit 342 through a passage 343 of the main control valve 24 (Fig. 4). The conduit 342 connects with the conduit I38 through a passage 344 of the valve 34 (Fig. 2). The conduit I38 connects with the passage I31 of the automatic brake valve 91 (Fig. 10). Since said passage I31 connects through the passages I39, I40 and MI of the valve 91 with atmosphere it is evident that the passage 305 of the distributing valve 210 will be open to exhaust when the valves I68, 24, 34 and 91 remain in normal position. The exhaust of pressure through the passage 305 and the connections above described can therefore be controlled by any of said valves last mentioned when in other than their normal positions.

The control of the application cylinder connections and the distributing valve release connections by the equalizing slide valve 289 will now be described.

When the distributing valve 210 is in normal or running position; as shown in Fig. 23, the passage. 299 of the equalizing slide valve 289 connects the application cylinder connections with the distributing valve release connections and as the distributing valve release connections are open to exhaust when the valves I68, 24, 34 and 91 are in normal position it is evident that the application cylinder connections, including the application cylinder 2" and the chambers H8 and 231, are likewise open to exhaust.

The equalizing slide valve 289 also acts as a control for the application portion of the distributing valve 210. This is accomplished in the following manner:

As there is no pressure in the application cylinder 2" the application piston 212 is therefore forced to the position shown in Fig. 23 which carries with it the application valve 218. This closes the port 219 and the main reservoir pressure delivered to the chamber 280 as above described is retained therein. The application piston 212 has the further function of moving the exhaust valve 215 to the position shown in the drawings (Fig. 23). In this position the pas sage 216 registers with one of the outlet openings of the passage 285 leading to atmosphere and, since the exhaust valve also opens the other outlet opening of the passage 285, any pressure that may be in the chamber 214 and also in the conduit 284 that connects with the brake cylinders of the locomotive and tender exhausts, since the conduit 284 connects into the passage 283 which is permanently connected with the chamber 214'. Therefore, the brakes of the locomotive and tender are in release position as long as the application cylinder 2'" is without pressure and the application portion of the distributing valve is in the position shown in Fig. 23.

The equalizing slide valve 289 further acts as a control for the application chamber 301 and the safety valve 309 of the distributing valve 210. As the passage 299 of the equalizing slide valve 289 connects the application chamber 301 through the passage 306 with the distributing valve release connections and furthermore, as the safety valve 309 is connected with the same connections because the passage 308 is in registration with the passage 303 through the passage 302, said passage 303 being connected with the passage 305 through the passage 299, it therefore follows that the application chamber 301, the safety valve 309 and the connections just described are open to atmosphere.

The equalizing slide valve 289 also acts as an indirect control for other connections, and chambers and passages in the elements of the braking system by its control of the application cylinder connections when in normal position. In order to clarify the description, these connections will be grouped first and the operation of the elements of the braking system directly concerned in their control will then be described.

This group of connections constitutes supply connections for the application cylinder connections and will be referred to hereinafter as the application cylinder supply connections. They include the conduit 2I2 which is connected at one end into the main control valve 24 (Figs. 4 and 5) and at its other end into the passage 2| I of the equalizing reservoir governor I84 (Figs. 13 and 18) The passage 2 is connected with the chamber 20! through the port 2I0. The chamber 201 is in turn connected with the passage 208 into which the conduit 209 connects. The conduit 209 connects into the passage 2 of the locomotive brake governor 2 (Figs. 15 and 20). The passage 2 is connected with the chamber 231 through the port 240. As the chamber 231 is a part of the application cylinder connections, it is therefore evident that theapplication cylinder supply connections are connected with the application cylinder connections at the port 240 of the locomotive brake governor. The purpose of these connections is to supp y a supplemental pressure to the application cylinder 2' of the distributing valve 210 as will be described hereinafter. However, it will suffice for the present to state that the pressure conditions in these connections are directly controlled by the valve 24, the equalizing reservoir governor I84, the locomotive brake governor 2 and the locomotive brake governor control valve 251, This control will now be described, considering the system as being in normal position.

It will be noted by reference to Fig. 4 that the conduit 2I2 is closed by the movable member 25 of the valve 24 when in normal position. It will be remembered that the valve plug 205 of the equalizing reservoir governor I 84 (Fig. 13) is forced downwardly to its seat 2I0 due to feed valve pressure being supplied to the chamber I99 above the piston 202 and that this has the effect of breaking communication between the chamber 201 and the passage 2| I.

As the conduit H2 is connected into the passage 2 it is evident that the conduit 2| 2 will be closed at both its outlet ends and does not function in this adjustment of the device The operation of the locomotive brake governor (Fig. 15) and the operation of the locomotive brake governor control valve (Fig. 17) in controlling the application cylinder supply connections will now be described. The locomotive brake governor 2I4 similar to the equalizing reservoir governor I84 constitutes an adjustable device. The tension of the spring 22I is adjusted to withstand a predetermined maximum range of pressure in the chamber 2I8. The locomotive brake governor control valve 251 also constitutes an adjustable device. The tension of the spring 26I is adjusted to withstand a predetermined maximum range of pressure in the passage 260 beneath the valve 259.

In considering the functioning of the device it will be assumed that the spring 22I is adjusted to withstand a pressure of 40 pounds while the spring 26I is adjusted to withstand a pressure of approximately 42 pounds.

There is a coordination between the adjustment of the springs 22I and 26I that is necessary to the functioning of the governor 2| 4 and the governor control valve 251, this function being to control the application cylinder supp y connections when the control system is in normal position. 'The purpose of this coordinated adjustment will become further apparent when the device is explained in its operation to application position, it being suflicient for the present purpose to state that, as the chamber 2I8 of the locomotive brake governor is without pressure in normal condition of the system due to the connection of said chamber 2I8 with the application cylinder connections, said application cylinder connections being open to atmosphere through the passage 299 of the equalizing slide valve 289 and the distributing valve release connections, as hereinbefore described, the spring tension of the spring 22I will force the piston 2I5 and the pin valve 2I9 downwardly, thus breaking communication between the chamber 2|8 and the passage 228 since the port 220 is closed. Since any pressure that would act in opposition to the spring 26l bearing against the valve 259 of the locomotive brake governor control valve 251 is supplied from the chamber 2I8 through the port 220 to the passage 250 beneath the valve 259 and since the port 220 is closed, it will be obvious that, since there is insuflicient pressure to raise the pin valve 2 I 9 from its seat, there will not be sufficient pressure in the passage 250 to force the valve 259 upwardly in opposition to the tension of the spring 26L The valve 259 of the locomotive brake governor control valve 251 (Fig. 17) will therefore be forced downwardly to its open position which results in the following operation:

The chamber 229 above the piston 232 is connected through the passages 228 and 230 of the governor 2 I4 with the conduit 23! which connects into the passage 260 of the control valve 251. The passage 260 connects with the chamber 264 through the restricted passage 263 in the valve 253. Since the chamber 264 connects with the chamber 266 through the passage 265, said chamber 266 being open to atmosphere through the exhaust port 261, it is evident that the chamber 229 of the governor 2I4 will be without pressure. Therefore, the piston 232 with its attached valve stem 234 and the valve plug 235 will be forced upwardly by the tension of the spring 233. This will open the port 240 that connects the chamber 231 with the passage 24I.

, As the passage 2 has connected thereinto the conduit 209 which, in turn, is connected into the passage 208 which leads to the chamber 201 of the equalizing reservoir governor it is evident that the chamber 201 will be connected with the chamber 231. Since this portion ofthe application cylinder supply connections is connected with the application cylinder connections by reason of being in communication with the chamber 231 and since the chamber 231 is open to atmosphere it follows that they likewise will be open to atmosphere so long as the equalizing slide valve 289 remains in the normal position, as shown in Fig. 23.

The apparatus is designed so that when all of the elements of the control system are in normal position the independent brake valve I68 may be operated to release the locomotive brake in the normal manner. Broadly, the application and release of the locomotive brakes under control of the independent brake valve is by controlling the pressure in the application cylinder of the distributing valve. The application of the locomotive brakes by the valve I68 in the usual manner is not interfered with nor changed regardless of the position of the various control elements, nor is the release operation of this valve when the control system is in normal position.

The group of conduits and passages associated with this release operation will now be described and they will be designated as the independent unrestricted release connections.

By reference to Fig. 12 it will be noted that the valve I68 is provided with the conduit I18 that connects into the passage I 11 in the valve. When the valve I68 is in running position the end of the passage I11 is closed by the rotary member I69 of said valve. The conduit I18 leads to the valve 24 and connects with a conduit 345 through a passage 346 in the movable member 25 01' the valve 24. The conduit 345 leads to the valve 39 and connects with a conduit 341 through a passage 348 in the movable member H of the valve 39. The conduit 341 then leads to the valve 34 through which it connects with the manifold exhaust conduit 8| through a passage 349 in the movable member 35 of the valve 34.

From this train of connections it will be understood that the passage I11 in the valve I68 is directly connected with exhaust and that so long as the valves 24, 39 and 34 remain in normal position the conduit I18 is likewise connected with exhaust. Therefore, by manipulation of the valve I68 to release position the conduit I18 may be placed in communication with the conduit I16 by the rotary member I69 of the valve I 68. Any pressure in the conduit I16 may therefore be released to atmosphere when it'is desired to release the locomotive brakes either in whole or in part by control of the pressure in the application cylinder connections. Therefore, the operator has the locomotive brakes under usual control so long as the valves controlling the conduit I18 remain in normal position.

The unrestricted operation of the valve I66 obtains only when the system is in normal condition. When the train and locomotive brakes have been applied through the control system the control through the valve I68 is restricted. The group of conduits and passages associated with the restricted operation of the valve I68 will now be described and they will be referred to hereinafter as the independent restricted release connections.

The connections comprise a conduit 350 which is closedat its inlet end by the movable member 25 of the valve 24, a passage 35I of the valve 39 and a conduit 352 connected into the conduit 241 at 353, which said conduit 241 is closed at its inlet end by the movable member 35 of the valve 34 and connected at its outlet end to the passage 246 of the restricted exhaust safety valve 243 (Figs. 16 and 21). These connections are associated with the application cylinder connections to effect a restricted release of the same through the conduit I16 when the valve I68 is placed in release position when the valve 24 or the valve 34 is in application position, as the independent restricted release connections are designed to change the independent unrestricted release connections into restricted ones. By reference to Fig. 5 it will be noted that when the valve 24 is in application position the conduit I18 is placed in communication with the conduit 350 through a passage 354 in which there is a groove 355 at its inlet end. Also by reference to Fig. 3 it will be noted that when the valve 34 is in application position the conduit 341 is placed in communication with the conduit 241 through the passage 349. It should therefore be borne in mind that so long as the control system is in normal position the independent restricted release connections for the valve I68 are inoperative.

The operation of the restricted exhaust safety valve 243 (Fig. 16) mentioned above will now be described.

The restricted exhaust safety valve 243 is an adjustable device, the spring tension of the spring 248 being adjusted so as to withstand a predetermined maximum range of pressure in the passage 246 beneath the valve 245. The adjustment of the spring 248 is in coordination with the springs 22I and 26I, the purpose of which is to control the governor 2H and the control valve 251, and through them the application cylinder supply connections. Upon the assumptions of pressures and adjustments heretofore made the spring 248 will be assumed to be adjusted to withstand a pressure of approximately 43 pounds. In the normal position of the system the passage 246 is without pressure and therefore the valve 245 is held in closed position as shown in Fig. 16. 4

The preliminary exhaust valve I I2 as previously explained is connected to and functions with the automatic brake valve 91. It will be remembered that the pressure on both sides of the equalizing piston 99 of the valve 91 is equal and that the equalizing piston stem I01 is held to its seat. The stem I 01 will therefore force the stem I64 and the element I63 downwardly against the tension of the spring I62. The tension of the spring I62 acting against the top of the valve I54 will force said valve I54 to its seat I59, thereby closing communication between the chamber I52 and the conduit I53.

As the conduit I53 is connected with a conduit 356 through a passage 351 having a groove 358 at one of its outlet ends in the movable member 35 ofthe valve 34, said conduit 356 connecting at 359 into the multiple exhaust conduit 8|, it is evident that the flap valve I54 will remain on its seat I59 due to. the absence of pressure in the conduit I53. The valve II2 will therefore remain in its normal or closed position.

In this position of the valve the bifurcated arm I66 will be free from the stem I64 and the element I63, the full purpose of which construction will be explained hereinafter.

The train control feed valve safety valve 3 is set to withstand a pressure of 50 pounds and is connected by a conduit 369 to the movable element 35 of the valve 34. The function of the train control feed valve 3 will be explained hereinafter when the valve 34 is described in application position.

From the foregoing description of the condition of the various connections and control devices of both the control system and the braking system in normal or running position it will be noted that so long as the valves I, 24, 34 and 39 of the control system remain in the normal position operation of the braking system in the normal manner by the operator through the man pulation of the valves I68 and 91 is not restricted or changed. This manipulation and its effect on the pump governor 3I6 and the distributing valve 219 and the train brakes connected with the brake pipe or train line follows the usual operation of these devices and further description is not therefore considered necessary.

From the normal or running position under the influence of the main electrical control valve a sequence of changes in the control system occurs, which operations will now be described:

Through any suitable means when the track conditions are unsafe the main electrical control valve I operates. The circuit with whichthe leads 3 and 4 are connected is de-energized, thereby de-energizing the field 2 of the valve I. When this occurs, through the action of the spring 6 and the action of the weight of the armature 5 and the carried valve structure, the armature is dropped. The movement of the armature results in the following change in condition in the control system:

The valve I2 seats and therefore closes the port I1 from the chamber I6 to the passage I8, thereby closing off the main reservoir pressure in the conduit 62. Simultaneously therewith the valve II opens. Therefore, the main reservoir pressure which is constantly supplied by the conduit 60 which enters the chamber I6 passes through the port I4 into the chamber 22, from which it leaves the valve through the passage 2I that connects with the conduit 21 leading to the application chamber of the valve 24. The exhaust of the conduit 21 to atmosphere is closed and it is supplied with main reservoir pressure. The conduit 21 formerly open to atmosphere now is supplied with main reservoir pressure from the chamber I6, the valve 9 being closed to prevent the escape of pressure from said conduit 21.

Likewise, simultaneously the valve I9 opens the port I3 and main reservoir pressure formerly in the passage I8 and the chamber I9 is exhausted through the passage 29 and the multiple exhaust conduit 65. Main reservoir pressure in the conduit 64, which under the normal setting of the control system is shut off by the movable member 39 of the valve 29, now exhausts through the passage 63 of the valve 39 and the conduit 62 which is connected with the passage I6 and the chamber I9. The pressure supplied to the conduit 64 provides means for returning the valve 24 to normal position following an application, but this pressure is immediately exhausted when the valve I assumes the application position so that there can be no pressure in the normal chamber of the valve 24 to act in opposition to pressure delivered to the application chamber thereof by the conduit 21 when the valve I is in application position and after the valve 29 assumes application position.

The second element of the control system to assume the application position is the main control valve 24. The admission of pressure to the application chamber of the valve 24 through the conduit 21 actuates the, movable member 25 of said valve to the position shown in Fig. 5. The pressure in the normal chamber is open to atmosphere through the conduit 26 and the conduit 12 and the multiple exhaust conduit 65, as the passages H and 10 ofthe valve 29 in normal position connect said conduits '28 and".

Simultaneously with the valve 24 assuming application position, the conduit 61 which is being supplied with pressure by reason of its connection with the conduit 21 is connected with the conduits 86 and 9I through the groove 68 and the passage 69. The conduit 88 as previously explained leads to the indicator 43 and, therefore, as the cylinder 44 is supplied with pressure, the spring-operated piston 45 is forced upwardly, thereby causing the semaphore arm 53 to assume the danger or horizontal position. This acts as an indication to the operator that the control system is moving to application position and. as heretofore stated, is the visible means for indicating to the operator the position of the valve 24. At the same time the audible means for indicating to the operator the condition of the system through the whistle 54 is brought into operation. Pressure supplied through the conduit 9|, the passage 92 of the valve 29, the conduit 93, the passage 94 of the valve 34 and the conduits 95 and 96 causes the whistle to sound an audible alarm that the control system is moving to the application position. These connections are, however, only temporary and the application of the valve 24 is promptly followed by the application of the valves 29 and 34.

The conduit 66 is now closed at its outlet end at the valve 24. The purpose of closing the conduit 66 will be explained hereinafter.

Pressure normally supplied to the conduit 86, upon the valve 24 assuming application position, exhausts through the conduit 90 since the passage 89 brings the conduit 66 into registration with the conduit 99. The purpose of these connections will be explained hereinafter.

The conduit 6| is constantly supplied. with main reservoir pressure and, upon the valve 24 assuming application position, is connected with the conduit 13 through the groove 86 of the passage 84 and a branch passage 36I. The conduit 13 is closed at its outlet end by the valve 39 in normal position but is connected at 362 with the conduit 32 which connects into the application chamber of the valve 29. The conduit 31 which leads into the application chamber of the valve 34 is also supplied with main reservoir pressu 

